Stabilized kerosene



Patented Jul 1 1,19

No Drawing.

Claims.-

. type in question go off color i. e., become darker in color, during storage or shipment involving substantial periods of time, particularly in .warm weather and in hot climates.. This is particularly true when these products are cased in small metal cans.

Although this discolorization may be reduced substantially in some cases by washing out all traces of ZnClz, FeCla or other soldering flux which was used in the manufacture of the cans, yet this procedure is both laborious and expensive and it is an object of the present invention to stabilize the color of such cased white products by a very simple and economic method.

Broadly, the invention consists in incorporating in the refined oil before storage or shipment. a small amount of a suitable stabilizing agent belonging to the class of chemical compounds known as ketones. called methyl-methyl ketone ordimethyl ketone,

is the simplest member of this class and has been found very effective as a color stabilizer according to the purview of this invention.

The type of refined oils intended to come within the scope of this invention includes petroleum distillates of approximately the kerosene boiling range, i. e., approximately 300 F. to 600 F., having fiash point not lower than about 100 F. having-a color suitable for marketing, whether these oils are untreated or whether they have been prepared by some decolorizing treatment such as clay treating, acid treating, and the like. These products may have been subjected to any of the other refining steps such as soda washing, sweetening, eta, which are commonly used in the art for finishing suchoils. These refined oils are used particularly for burning in lamps and ranges and a water white color is generally considered an indication of an oil which has satisfactory burning qualities. For example, U. S. Government specifications for kerosene call for a Sayb'olt color not lower than 16 while for long time burning oil" the minimum color is 21.

In an attempt to predict the. tendency of a refined oil to become discolored during storage the so-called color hold test has been used; this involves inspection of the color after heating a sample of the oil for 16 hours at 212 F. Although sometimes there is a fair correlation between the color hold test and the actual storage stability as measured by inspection of the color periodically during actual storage of samples of suitable size, for instance, one gallon cans, yet in many cases the color hold test is not a Acetone, which may also be 2,165,261 STABILIZED KEROSENE Development Company, a corporation of Delaware Application November 28, 1936, Serial No. 113,250

satisfactory basis for predicting the storage stability. i

A comparison of these two tests as applied to a number of other refined oils is shown in the following Table 1. TABLE 1 Storage stability l i id C l C l o 0 or 0 or Refined oil Color 1 2 drop Months pgi tg d s e smmge' months storage Refined oil 1 from source 26 26 N l Refined oil 2 from i 0 +19 source Z3 22 1 .1 Refined ill 3 from 2 +20 source 22 21 l l l Refined oil from 2 8 source B +21 "+18 3 15-18 Straw. Kerosene from source I .+24 +21 3 6 Straw. Kerosene irom source D +26 +17 9 9 Straw.

The present invention should not be confused with the use of anti-oxidants for petroleum oils, such as gum inhibitors in gasoline, etc., for it has been found that a number of substances which have definite values as gum inhibitors in gasoline, for example, tricresol, or light stabilizers for gasoline, for example, naphthalene, and butyl amines, distinctly'accelerate color loss' in refined oils such as kerosene and the like.

In carrying out the present invention only a relatively small amount of stabilizer is required, for instance, between the approximate limits of 1 to 10 cc. per gallon of refined oil. 10 cc. per gallon corresponds approximately to 0.25% by volume. Although the amount required to produce the best results with the least cost will vary to a certain extent according to the source of crude from which the refined oil was prepared and will depend upon the refining steps to which it had been subjected as well as the severity of the conditions, i. e., temperature, time, etc., under which it is intended to be stabilized,

.generally about 3 cc. of stabilizer per gallon of yl butyl ketone, diisopropyl ketone, methyl phenyl ketone, quinone, etc. .Although acetone is sufficiently soluble in refined oils for-the purpose in question it may be desirable to use a small alnount of a mutual solvent for some of the less soluble ketones. I I

Having thus described the general principles of the invention some experimental data are given Table 2 shows the efiect of several commercial antioxidants on the color stability of a kerosene a tram source C, the original inspection or which showed a color of +24, color hold +21 and morcury No. .7,

- Tm: ll

Btabllit trend on storage in gallon oans wolor alter the following Materhl added mm) Thedatainthe above'lable'S mightbesummariaed as follows:

In other words acetone reduced the 18 months storage color loss from 7 to 4 while the hydroquinone increased the color loss both when dissolved in acetone and in alcohol.

g Inasmuch as a large quantity or refined oil is exported from this country into foreign coun- 2 tries and considerable trouble results from the 7 shipment 01' such refined oils into countries situjg ated vin hot climates, a number or cases 01' refined oil from source A were actually shipped from the United States to Dutch Guiana (where the average yearly temperature is much warmer i m i than in New York, for example), stored there pl w stored il a room Whch the for 14 months and then inspected after return o'le'nfifid;ii%il2t:o%tlmi%3% 5 to m g l l z sg a ls some or es var one s s were a a ways leav- MW mgpecflm l ing a blank sample in the same case, and ten Th8- dltfi in Table 2 show that the various mes being tested for each stabilizer, commercial anti-oxidants tested failed to improve Tu 4 the color stability of the kerosene used and, in E t t tact, several or the addition agents actually ac- 8 rented the 10 or colon ORIGINAL INSPECTION or REFINED on. USED In the tollowing table data are given showing the eflect of acetone on the color stability or numbmd sweetened water white kerosene, the original in- H Ho spection of which showed a color of +26, color hold +26; and mercury No. 4. +22 For the sake of comparison some tests are also +21 +21 included on hydroquinone in acetone solution and 4 in alcohol solution. v

' OOLOB 0F SAMPLES AFTER SHIPPING AND RETURN BerieeA ScrleeB SeflceO v v I I Commerone gw Acetone .Blank 'm mm:

. in it; #2 +21 +1: +21 +17 Straw +22 +5 -0 is 1i: 1:: +21 +10 +2 +22 +1: Below-H Amounts oi stabilizers used:

' $32 1; lamin 0.811) n'filopl x Comm anti-oxidant No. a o.sibI/iooo m1 Test: 3 The above Table 4 shows that acetone successfully maintained a color +21 or +22 subs billt n d to i all @ficofir :i te r 3: 6115.132 stantially the same as the original color (+22 w ms 11mm) or +23) whereas the blank samples in cases 1' o 1 s s o i2 15 1a to 5 had dropped to an average color less than 1and those in cases 6 to 10 had dropped to an average color or about +18. Table 4 also shows that trl-normal-butyl amine and commercial anti-oxidant #2 both accelerated the color loss.

Results of tests to determine the eil'ect of the added acetone on the burning quality of refined I 011 are shown in the following table:

TABLE 5 Refined oil+3 cc. Refined acetone per gallon Gravity 46.6 46.6. Refined oil viscosity 355 355. Consumption-(fluid ounces burned 8 Not excessive soft, Not excessive soft,

dull, slightly disdull, slightly disintegrated. integrated. Flame Shape satisfactory.-. Shape satisfactory. Burning quality Satisfactory Satisfactory.

Table shows that the acetone had no appreciable effect on the burning quality of the refined oil (kerosene) tested.

Thus the unexpected improvement in stability of the refined oils isobtained without any attendant deleterious effects.

It is not intended that this invention be limited to the specific examples which are given here only for the sake of illustration, nor to any theory as to the operation of the invention, but only by the appended claims in which it is intended to claim all novelty inherent in this invention as broadly as the prior art permits.

We claim:

1. A stabilized refined oil consisting of a petroleum distillate having a boiling point range of from about 300 to about 600 F. and having a flash point of more than 100 F., and a lower aliphatic ketone in an amount between about .025% and about 0.25% by volume of the petroleum distillate.

2. A composition as in claim 1 wherein the lower aliphatic ketone is acetone.

3. A composition as in claim 1 wherein the lower aliphatic ketone is acetone present in an amount of about .08% by volume of the petroleum distillate.

4. The stabilized product consisting of kerosene having a boiling point range of from about 300 F. to about 600 F. and between about 025% and about 0.25% by volume of acetone, the mixture being cased in metal containers.

5. The method of stabilizing a petroleum distillate having a boiling point range of from about 300 to about 600 F. and having a flash point of more than 100 F. which consists in adding to said distillate between about .025% and about 0.25% by volume of a lower aliphatic ketone.

6. Process as in claim 5 wherein the lower aliphatic ketone is acetone.

7. Process as in claim 5 wherein the lower aliphatic ketone is acetone used in an amountof about .08% by volume of the petroleum distillate.

8. The method of stabilizing a petroleum distillate having a boiling point range of from about 300 to about 600 F. and having a flash point of more than 100 F. and which is cased in metal containers which consists in adding between about 1 cc. and about cc. of a lower aliphatic ketone per gallon of petroleum distillate.

9. The process as in claim 8 wherein the lower aliphatic ketone is acetone.

10. The process as in claim 8 wherein the lower aliphatic ketone is acetone and used in an amount of about .08% by volume of the petroleum distillate.

AMIOT P. HEWLETT. GERALD E. PHILLIPS. 

